During production of articles of manufacture within an assembly line, indication devices are typically used to keep track of activity related to selected work pieces within the assembly line. Referring to FIG. 1, an example indication device is a marker 102 that is used to mark a work piece to confirm completion of a predetermined treatment to that work piece. In FIG. 1, an example assembly line includes a first work piece 104 having a first bolt 106, a second work piece 108 having a second bolt 110, and a third work piece 112 having a third bolt 114. The articles of manufacture within the assembly line of FIG. 1 may be automotive parts for example. However, the present invention may be applied within assembly lines for producing any type of articles of manufacture as would be apparent to one of ordinary skill in the art from the description herein.
As the assembly line, including the work pieces 104, 108, and 112, progresses, an operator within the assembly line uses the indication device such as the marker 102 to make a mark on a work piece. The mark on a work piece indicates that predetermined treatment has been performed on that work piece such that further treatments may be applied to that work piece. Referring to FIG. 1, for example, an operator within the assembly line makes a first mark 116 on the first work piece 104 after checking that the first bolt 106 has been properly threaded onto the first work piece 104 with a proper torque force. Such a mark 116 on the first work piece 104 ensures that the first work piece 104 meets the quality standards for further processing of the first work piece within the assembly line. Thus, proper use of an indication device, such as the marker 102, on a work piece may indicate completion of testing that work piece.
Alternatively, the marker 102 may be applied to make a mark on a work piece to indicate inclusion of a critical part to the work piece. For example, a mark may be made to an automobile engine to indicate that engine oil has been injected into that automobile engine. With such a mark, an operator within an assembly line may properly run the automobile engine for testing with assurance that engine oil has already been injected into the engine.
Referring to the example of FIG. 1, the operator makes a second mark using the marker 102 on the second work piece 108 after the operator checks that the second bolt 110 has been properly threaded onto the second work piece 108 with a proper torque force. Subsequently, the operator makes a third mark using the marker 102 on the third work piece 112 after the operator checks that the third bolt 114 has been properly threaded onto the third work piece 112 with a proper torque force. If the operator works on the work pieces 104, 108, and 112 using a regular schedule within the assembly line, the marker 102 is used to make a mark on a work piece within every predetermined time period.
Unfortunately, with the prior art indication device, such as the simple marker 102, an operator within an assembly line may fail to properly use the indication device. The operator may properly fail to make a mark on the work piece after also failing to apply the proper treatment to the work piece. Alternatively, the operator may forget to make a mark on a work piece even after proper treatment to the work piece. In either case, a subsequent operator may act to correct an expected flaw. When such a flaw has not actually occurred, both time and money are wasted.
In any case, an improved indication device is desired for ensuring proper use of the indication device on each work piece after applying the proper treatment to each work piece within the assembly line.